The use of chlorofluorocarbons or hydrochlorofluorocarbons as foam-blowing agents has been banned due to concerns that their release damages the ozone layer. More recently, foam-blowing (addition of a volatile material to a polymeric mixture to cause a bubbled matrix which imparts insulation or cushioning value) has been accomplished through use of HFC-245fa; however, concern has been raised about the Global Warming Potential of this material.
Trans-1,3,3,3-tetrafluoropropene (HFO-1234ze (E)) and trans-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd (E)), two low GWP molecules, have been identified as a new generation of more environmentally friendly blowing agents. Both molecules have other potential applications, such as for example, as solvents, refrigerants, aerosols, and as building blocks for making other fluorinated compounds. It is foreseeable that there will be a transition period during which all three products, i.e., HFO-1234ze (E), HCFO-1233zd (E), and HFC-245fa, will be needed. It is, therefore, desired to develop an integrated process in which all three products can be manufactured for efficiencies and synergies.
Methods for separately producing these three products are known in the prior art. U.S. Pat. No. 6,844,475, which is hereby incorporated herein as a reference, teaches a process for producing HCFO-1233zd in a liquid phase reaction at a temperature of less than 150° C. in the presence of a Lewis acid catalyst or mixture of Lewis acid catalysts, and hydrogen chloride and HCFO-1233zd formed in the reaction are continuously removed and the HCFO-12333zd is isolated.
The preparation of HFC-245fa is realized in a one-step process as disclosed in U.S. Pat. No. 5,574,192, or in a two-step process, as disclosed in WO 97/24307 and in U.S. Pat. No. 6,362,383. In a two-step process, HCC-240fa first reacts with hydrogen fluoride to give HCFO-1233zd, which reacts in a second step with hydrogen fluoride to give HFC-245fa.
The preparation of HFO-1234ze (E), from HFC-245fa is taught in U.S. Pat. Nos. 7,230,146 and 7,485,760, the disclosures of which are hereby incorporated herein by reference.
Accordingly, the present invention provides an integrated process to co-produce these three compounds (HCFO-1233zd, HFC-245fa, and HFO-1234ze), starting from one feed material, namely a tetrachloropropene, or mixtures of such compounds, and the production amount of each of the products can be easily adjusted depending on market demand by simple adjustments of the process.